Magnetic Resonance ImagingPhase 2NCT06629077
Brain Blood Vessel Responses to Changes in Blood Flow
A Phase 2 study testing MRI and Prazosin in people with Magnetic Resonance Imaging and Cerebrovascular Circulation, run by University of Wisconsin, Madison at 1 site in United States.
Trial summary
Brain blood flow will be measured during a simulated postural change test and while breathing increased levels of carbon dioxide using magnetic resonance imaging. Read more about this study
- Who is it for?
- Ages 55 to 69 yearsHealthy volunteers can take part
- Conditions the study is for
- Magnetic Resonance Imaging, Cerebrovascular Circulation
- What is being tested?
- MRI and Prazosin
- Type of treatment
- Pill or oral medicine, Medical device
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 36 participants
- Where
- 1 siteUnited States
- Study dates
- 26 Feb 2026to May 2027
- Phase
- Phase 2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 55 to 69 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Between the ages of 55-69 years
- Have a BMI less than or equal to 34.5 kg/m2
- Nonsmoker
- are less than 72 in (182.88 cm) height
- Females must be postmenopausal
Who cannot join
- Diagnosis of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD)
- History or evidence of hepatic disease, hematological disease, or peripheral vascular disease; severe kidney injury requiring hemodialysis
- History of cardiovascular disease including: severe congestive heart failure, coronary artery disease, ischemic heart disease (stents, coronary artery bypass grafts) and tachycardia
- Uncontrolled hypertension
- History of clinically significant ischemic or hemorrhagic stroke, or significant cerebrovascular disease
- Severe untreated obstructive sleep apnea
Show all 15Show fewer
- History of diabetes with HbA1c greater than 9.5%
- Major neurologic disorders other than dementia (e.g., MS, ALS, brain surgery, etc.)
- Current or recent (\<1 year) major psychiatric condition (Axis I) or addictive disorders
- Significant surgical history
- Other significant medical conditions at investigators' discretion
- Contraindications to MRI
- Prescribed medications that interfere with prazosin
- Lactose allergy
- lower body will not fit in lower body negative pressure (LBNP) chamber (regardless of overall height and BMI).
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Wisconsin
Madison, Wisconsin, 53705
Anna J Howery, MS, 608-262-9572, barneslab@education.wisc.edu
Jill N Barnes, PhD
About this study
Official title: Cerebrovascular Responses to Acute Hypoperfusion
Brain blood flow will be measured during a simulated postural change test and while breathing increased levels of carbon dioxide using magnetic resonance imaging.
Read the detailed description
Global cerebral blood flow (CBF) decreases with advancing age; however, some adults have accelerated declines in CBF, placing them at a greater risk of cognitive impairment. However, there is a lack of human studies that investigate the cause or consequence of altered blood flow regulation in the brain. This study will systematically address this gap in knowledge by examining cerebrovascular control in adults during acute physiological challenges (simulated postural change test and breathing increased carbon dioxide) that stimulate a change in CBF.
- Being tested
- MRI, Prazosin, Placebo
- Keywords
- Magnetic Resonance Imaging, Brain Blood Flow, Lower Body Negative Pressure, Carbon Dioxide
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MRIDevice
Participants will undergo an MRI scan while performing breathing and a simulated postural change task.
PrazosinDrug
A dose of prazosin will be administered based on body weight.
PlaceboDrug
Oral placebo
| Study group | Role | What they receive |
|---|---|---|
| Middle-Aged Adults | Experimental | Middle-Aged Adults between 55-69 years of age. Receives: Device: MRI; Drug: Prazosin; Drug: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in blood flow
The change in intracranial blood flow during breathing and simulated postural change tasks will be measured with MRI
Measured: Two study visits, up to 240 minutes
Change in blood velocity
The change in blood velocity during breathing and simulated postural change tasks will be measured with MRI.
Measured: Two study visits, up to 240 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Oct 2024
- Study start26 Feb 2026
- Primary completionMay 2027 (estimated)
- Study completionMay 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Magnetic Resonance ImagingStudies of the same condition, open and under way.
- More trials run by University of Wisconsin, MadisonThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 36 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Wisconsin, Madison
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Jill Barnes, PhD, Principal investigator, UW Madison
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06629077
- Sponsor's protocol ID
- 2024-0377
- Other IDs
- 1RF1NS117746-01, A176000, EDUC/KINESIOLOGY, Protocol Version 8/11/2026
- Status last verified
- Sep 2026
- First submitted
- 4 Oct 2024
- Last updated
- 15 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Cerebrovascular Responses to Acute Hypoperfusion
- ClinicalTrials.gov ID
- NCT06629077
- Acronym / sponsor ID
- 2024-0377
- Keywords
- Magnetic Resonance Imaging, Brain Blood Flow, Lower Body Negative Pressure, Carbon Dioxide
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 36 participants (estimated)
- Lead sponsor
- University of Wisconsin, MadisonUniversity, hospital or other
- Collaborators
- National Institute of Neurological Disorders and Stroke (NINDS)
- Study start
- 26 Feb 2026 (actual)
- Primary completion
- May 2027 (estimated)
- Study completion
- May 2027 (estimated)
- First posted
- 8 Oct 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Brain blood flow will be measured during a simulated postural change test and while breathing increased levels of carbon dioxide using magnetic resonance imaging.
Detailed description
Global cerebral blood flow (CBF) decreases with advancing age; however, some adults have accelerated declines in CBF, placing them at a greater risk of cognitive impairment. However, there is a lack of human studies that investigate the cause or consequence of altered blood flow regulation in the brain. This study will systematically address this gap in knowledge by examining cerebrovascular control in adults during acute physiological challenges (simulated postural change test and breathing increased carbon dioxide) that stimulate a change in CBF.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Middle-Aged Adults | Experimental | Device: MRI, Drug: Prazosin, Drug: PlaceboMiddle-Aged Adults between 55-69 years of age. |
Who may qualify
- Ages
- 55 to 69 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Between the ages of 55-69 years
- Have a BMI less than or equal to 34.5 kg/m2
- Nonsmoker
- are less than 72 in (182.88 cm) height
- Females must be postmenopausal
Key exclusion criteria (15 listed)
- Diagnosis of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD)
- History or evidence of hepatic disease, hematological disease, or peripheral vascular disease; severe kidney injury requiring hemodialysis
- History of cardiovascular disease including: severe congestive heart failure, coronary artery disease, ischemic heart disease (stents, coronary artery bypass grafts) and tachycardia
- Uncontrolled hypertension
- History of clinically significant ischemic or hemorrhagic stroke, or significant cerebrovascular disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| MRIParticipants will undergo an MRI scan while performing breathing and a simulated postural change task. | Device | Middle-Aged Adults |
| PrazosinA dose of prazosin will be administered based on body weight. | Drug | Middle-Aged Adults |
| PlaceboOral placebo | Drug | Middle-Aged Adults |
Primary outcome
Change in blood flow
Time frame: Two study visits, up to 240 minutes
The change in intracranial blood flow during breathing and simulated postural change tasks will be measured with MRI
Change in blood velocity
Time frame: Two study visits, up to 240 minutes
The change in blood velocity during breathing and simulated postural change tasks will be measured with MRI.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Jill Barnes, PhD principal investigator
UW Madison
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing MRI and Prazosin in people with Magnetic Resonance Imaging and Cerebrovascular Circulation, run by University of Wisconsin, Madison at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Anna Howery (608-262-9572, ahowery@wisc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in blood flow (time frame: Two study visits, up to 240 minutes). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Sep 2026.